Yunus, who recently penned the book Creating a World Without Poverty: Social Business and the Future of Capitalism, spoke at two events organized by the World Affairs Council of Houston on Monday.

He suggested that people create businesses with a societal motive, offering health insurance, check-cashing services or bank accounts for the poor, for example. He envisions investors would recoup their investment, but instead of focusing on making profits, their goal would be to fix societal and environmental ills.

Yunus began working with the impoverished more than three decades ago when he borrowed money from a Bangladeshi bank and, in turn, loaned that money to villagers because the poor did not qualify for loans.

In 1983, he launched the Grameen Bank, or "village bank," considered the pioneer of microcredit. The bank now has 7.5 million borrowers in Bangladesh who take out money for small businesses, an education or home loans, which are repaid with interest. The bank also runs a program for beggars, who borrow an average of $15 interest-free to sell wares from door to door.

The model of loaning small sums to the working poor has been duplicated across the globe by for-profit and nonprofit organizations. That global contagion of microloans helped lead to Yunus and the Grameen Bank winning the 2006 Nobel Peace Prize.

But the microcredit movement has its critics.

"The biggest myth about this is that it goes to start a business," said Thomas Dichter, the co-editor of What's Wrong With Microfinance?

Borrowers use the money to survive, by earning a few pennies a day, selling bags of rice or cups of tea, he said.

"Let's not make the mistake that these are mini-entrepreneurs or future Bill Gateses. They are not," said Dichter, an international development consultant. "They are just trying to get by."

He also said microcredit borrowers are still poor in Bangladesh, one of the world's poorest nations.

But Yunus, in a gathering with reporters after his speech, said that 64 percent of the bank's clients who have borrowed from Grameen for five years or more "have crossed the poverty line."

"Microcredit alone does not solve the problem of poverty," Yunus said. "Microcredit is a tool to get out of poverty."